Air-pump



LEVI LEANDER LAB/SON, OF LOS ANGELES, CALIIEOliLIil'Ili..`

Ain-PUMP.

nseaeea Specification of Letters Patent.

Patented Nov. 29, 1921.

Application filed December 22, 1920. Serial No. 432,606.

To @ZZ whom t may concern:

Be it known that l, LEVI LnANnnn LARsoN, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Air-Pumps, of which the following is a specification.

1t is the object of this invention to provide an air pump having a reciprocating piston and forming suction and compression strokes at the respective faces of the piston and upon the strokes in opposite directions, the air compressed at one side of the piston being discharged to the opposite side ot the piston at the end of the stroke causing compression oi the same7 so that at the succeeding stroke in the opposite direction all of the air will be discharged through a common outlet.

It is a further object of the invention to provide means whereby the compression of air at one side of the piston will cause compression of spring means so arranged that at the end of the stroke the spring means will expand to force the air to the opposite side or' the piston so that during the succeeding stroke all of the air' will be discharged through the common outlet.

The invention will be readily understood from the following description of the accompanying drawings, in which Figure 1 is a longitudinal section through a pump constructed in accordance with the invention.

Figs. 2 and 3 are transverse sections on the lines 2-2 and 3-3 of Fig. 1.

The pump consists of a cylinder 1 preferably arranged in vertical osition and having the base 2 provided wit. an inlet port 3 leading to the cylinder and having an inwardly opening check valve Ll therein. The base is also provided with an outlet port 5 leading from the cylinder and connected to a usual flexible conduit 6.

A usual piston head 7 is arranged within the cylinder and is connected to a piston rod 8 extending upwardly through the cylinder and beyond the upper end cap 9. The end of the rod may be provided with a usual handle 10.

End cap 9 is of greater diameter than cylinder 1, and is connected to an outer cylinder 11 which extends downwardly over the upper end of cylinder 1 with the end of cylinder 11 turned inwardlyas shown at 12, so as to rest against the cylinder.

A stop shown as a cotter pin 13 extends transversely of cylinder 1 adjacent the upper end of the same with piston rod 8 sliding freely through the cotter pin. A sleeve 111 is mounted upon the exterior of cylinder 1 below cotter pin 13 and at its lower end is provided with an annular ange 15 closing the space between cylinder 1 and cylinder 11. A packing' ring 16 is received upon this flange and is held in position by a ring 17,

so as to form an airtight partition between the spaces provided between cylinders 1, and 11 above and below the partition and shown at 18 and 19. A coil spring 2() is received in chamber 19 with one end thereof abutting against the end lip 12 of cylinder 11, and its opposite end abutting against flange 15. The chamber 18 communicates with the interior of cylinder 1 by ports 21 extending through sleeve 141 and cylinder 1, and when cylinder 11 and end cap 9 are elevated with relation to cylinder 1, the chamber 18 also communicates with'cylinder 1 above the upper edge of the wall of said cylinder.

Piston rod 8 is loosely received through end cap 9 as shown at 25, so that air may normally enter the upper end of cylinder 1, but a valve 23 is mounted upon the piston rod so as to close this air inlet into the upper end of cylinder 1 when'valve 23 is moved upwardly with the piston rod. rllhe valve frictionally engages the piston rod so that as the latter is elevated, the valve is lifted until it abuts against end cap 9 for closing the air inlet, and thereafter as the piston rod continues its upward movement, it will slide through valve 23. `Upon the return stroke of the piston rod the valve will be moved with the same, so as to open the air inlet, and when it abuts against cotter pin 13, the piston rod will slide through the valve as it continues its stroke.

The operation of the pump is as follows, assuming the parts to be in the position illus` trated in the drawings with the pump head adjacent the limit of its downward stroke and cylinder 11, and cap 9 moved downwardly by the expansion of spring 20 until cap 9 rests upon the upper edge of the wall of cylinder 1:

Upon the up stroke of the piston, air is drawn into the lower part of cylinder 1 through inlet 3, and valve 23 moves to close air inlet 25. The air above piston head 7 is forced through ports 21 into chamber 18, and as the compression of this air increases, cylinder 11 and cap 9 will be raised from cylinder 1 against the action of spring 20.

By this arrangement when the piston head reaches its upper limit of movement, a con pressed body of air is formed in chamber 1S and in the upper end of cylinder 1.

The upward stroke of the piston is limited by cotter pin 13, and when the piston has reached this position, it has moved vbeyond ports 21, so that the latter communicate with the cylinder below the piston.v As a consequence the compressed air in the upper end of the cylinder and in chamber 18 flows through ports 21 to the cylinder below the piston. The expansion of spring 2O during this discharge of air tending to contract the size of chamber 18 will assist in forcing the air into cylinder 1 below the piston.

Upon the succeeding down stroke of the piston the air sucked into the lower end of the cylinder upon the up stroke of thepiston, and the compressed air discharged into the cylinder below the piston as just described,

will be compressed and discharged through the outlet 5 and the flexible conduit 6.

Various changes may be made without departing from the spirit of the invention as claimed.

What is claimed is:

l. A-pump comprising a cylinder having a reciprocating piston, means for creating suction and compression at the opposite faces of the piston upon the respective strokes thereof, means comprising a spring compressed at one stroke by the fluid compression at one face of the piston, means for permitting the expansion of said spring at the end of said stroke so as to discharge the compressed iuid to the cylinder at the opposite face ofthe piston, and means for discharging the fluid at said face of the piston upon the opposite compression stroke. y

2. A pump comprising a cylinder having a reciprocating piston, means for creating suction and compression at the opposite faces of the piston upon the respective strokes thereof, an eXpandible chamber adapted to receive the fluid compressed at one face of the piston and upon one stroke thereof, means comprising a spring compressed by the expansion of said chamber, means for permitting the expansion of said spring and contraction of said chamber at the end of said stroke so as to discharge the compressed fluid to the cylinder at the opposite face of the piston, and means for discharging the fluid at said face of the piston upon the opposite compression stroke.

A pump comprising a cylinder having a reciprocating piston, luidinlet valves in the cylinder beyond therespective faces of said piston, a discharge in said cylinder beyond one face of the piston, a chamber having a port communicating with the opposite end of the cylinder, said port arranged so that the piston passes beyond the same at the end of its stroke away from the discharge.

4. Arpump comprising a cylinder having a reciprocating piston, fluid inlet valves in the cylinder beyond the respective faces of said piston, a discharge in said cylinder beyond one face of the piston, a chamber having a port communicating with the opposite end of the cylinder, said port arranged so that the piston passes beyond the same at the end of its stroke away from the'discharge, said chamber being expandible and contractible, and spring means yieldably tending to contract said chamber.

In testimony whereof I have signed my name to this specification.

LEVI LEANDER LARSON. 

